A good site for more information is found in the link noted on this post. However, here's some basic tips....
- Only use Arial as the font or letter style - not all computers read the same fonts
- Keep the font size 11-14 points
- Line length should be 65 characters which means, letters, symbols and spaces
- Do not use bullets - I personally use the minus sign (-) or an asterisk (*)
- Use upper and lower case letters - capitalize the job title and the section headings. Do NOT capitalize more than 3 words in one grouping/phrase.
- Use key words (industry buzz words)
- Align all lines on the left - do NOT justify both margins.
- Spell check - at least 2 or 3 times
- Do not use a tab bar - use your space key instead